(1). Field of the Invention
The present invention pertains to a low cost construction of a hand held and hand operated liquid dispenser. In particular, the present invention pertains to a hand operated liquid dispenser of simplified construction that reduces the number of component parts of the dispenser and thereby reduces the dispenser's manufacturing cost. The dispenser's simplified construction provides a dispenser having a pump plunger that is manually reciprocated along a straight line of movement to operate a pump and dispense liquid from the dispenser. A liquid discharge passage extends through the pump plunger and communicates the pump with a liquid discharge orifice on the pump plunger. The liquid discharge orifice dispenses liquid from the liquid dispenser in a desired discharge pattern that is directed along the line of reciprocating movement of the pump plunger.
(2). Description of the Related Art
Hand held and hand operated liquid sprayers are well known in the liquid sprayer art. Typically known as trigger sprayers, these sprayers are commonly used to dispense household cleaning or cooking liquids in a stream or spray pattern or as a foam. A trigger sprayer is typically connected to a plastic bottle containing the liquid dispensed by the trigger sprayer.
A typical trigger sprayer is comprised of a sprayer housing that is connected to a neck of the bottle of liquid by a threaded connection or a bayonet-type connection. The sprayer housing is formed with a pump chamber, a vent chamber, a liquid discharge passage, and a liquid supply passage. The liquid discharge passage communicates the pump chamber with an outlet orifice of the trigger sprayer. The liquid discharge passage often contains a liquid spinner. The liquid supply passage communicates the pump chamber with a dip tube that extends into the liquid in the bottle when the trigger sprayer housing is attached to the bottle neck.
A pump piston is mounted in the pump chamber for reciprocating movement of the piston through the chamber. The pump piston moves in a direction out of the pump chamber to increase the interior volume of the pump chamber. This movement of the piston draws liquid through the dip tube and the liquid supply passage and into the pump chamber. The pump piston moves in a direction into the pump chamber to decrease the interior volume of the pump chamber. This movement of the piston pumps liquid from the pump chamber through the liquid discharge passage and out of the trigger sprayer. A spring is provided in the pump chamber for biasing the pump piston in the direction out of the pump chamber.
A vent piston is connected to the pump piston. The vent piston is received in the vent chamber for reciprocating movement between opened and closed positions of the vent piston in the vent chamber. In the opened position of the vent piston, the interior of the bottle attached to the trigger sprayer is allowed to vent through the vent chamber to the exterior environment of the trigger sprayer. In the closed position of the vent piston, the interior of the bottle is closed to the exterior environment preventing unintended leakage of the liquid contents of the bottle through the vent chamber to the trigger sprayer exterior environment.
A trigger is mounted on the sprayer housing by a pivot connection. The trigger is also connected to the pump piston and the vent piston. Repeating the sequence of manually squeezing the trigger toward the sprayer housing against the bias of the pump chamber spring, and then releasing the trigger oscillates or pivots the trigger about its pivot connection. The pivoting movement of the trigger reciprocates the pump piston in the pump chamber and reciprocates the vent piston in the vent chamber.
A pair of check valves or one-way valves are assembled in the sprayer housing to control the flow of liquid through the liquid supply passage, the pump chamber, and the liquid discharge passage. One of the check valves is positioned between the liquid supply passage and the pump chamber. This check valve controls the flow of liquid through the dip tube and the liquid supply passage to the pump chamber, and prevents the reverse flow of liquid. A second of the check valves is positioned between the pump chamber and the liquid discharge passage. This second check valve controls the flow of liquid from the pump chamber through the liquid discharge passage, and prevents the reverse flow of liquid.
A nozzle assembly having a liquid discharge orifice is assembled to the sprayer housing at the outlet of the liquid discharge passage. The liquid spinner in the liquid discharge passage has a liquid swirl chamber at an end of the spinner. The swirl chamber imparts a spin to the liquid pumped through the liquid discharge passage just prior to the liquid being discharged through the liquid discharge orifice of the nozzle. The nozzle of many trigger sprayers can adjust the pattern of liquid discharge from the trigger sprayer by rotating the nozzle relative to the sprayer housing. The nozzle can often be rotated between an off position where liquid discharge from the trigger sprayer is prevented, to a spray position where liquid is discharged from the trigger sprayer in a spray pattern, to a stream position where liquid is discharged from the trigger sprayer in a stream pattern, to a foam position where liquid is discharged from the trigger sprayer as a foam, or any combination of these liquid discharge patterns.
From the manual oscillating movement of the trigger on the sprayer housing, the pump piston is reciprocated in the pump chamber. This results in liquid being drawn from the bottle through the dip tube and past the first check valve to the pump chamber. The liquid is then pumped from the pump chamber past the second check valve and through the liquid discharge passage. The liquid passes through the liquid spinner and the liquid discharge orifice of the nozzle and is dispensed from the trigger sprayer.
The typical trigger sprayer described above has many separate component parts. The manufacturing of each of these separate component parts and their assembly into the trigger sprayer contributes to the overall manufacturing cost of the trigger sprayer. Because the typical trigger sprayer is manufactured and sold in very large numbers, even the slightest reduction in the manufacturing cost of a trigger sprayer design can result in a significant overall reduction in the cost of manufacturing large numbers of trigger sprayers. Thus, it is desirable to reduce the number of separate component parts of a manually operated liquid dispenser to reduce its manufacturing costs.